The present invention relates to methods and apparatus
cleaning the interior surfaces of papermachine headbox plenums.
Papermaking fiber and many performance enhancing compounds combined with the fiber to formulate a papermaking stock or furnish have either chemical or electrostatic tendencies to deposit upon or adhere to papermachine confinement or conduit surfaces. For such reasons, flow condition critical internal surfaces within a papermachine headbox are highly polished and are frequently cleaned.
Among such surfaces are those of a hydraulic or bunched tube headbox slice plenum. Converging interior surfaces of the headbox slice walls funnel stock flow between the walls into a slice nozzle for discharge upon a traveling, fourdrinier drainage screen.
The interior surfaces of these slice walls are highly polished and sometimes plated to inhibit accumulations of these contaminants. Nevertheless, imperfections remain as nucleating sites for contamination growth and spread.
Traditional air padded headboxes were voluminous enough for internal occupancy by workmen having access to nearly all the internal surface area. Periodically, accumulated deposits upon such internal surfaces were removed by manual scouring.
The advent of bunched tube headboxes essentially eliminated the internal headbox volume and replaced it with a high flow volume manifold connected to a slice plenum by a multiplicity of tubular conduits. All of these headbox interior surfaces are conveniently accessible for scouring, either by design or by tool; except the slice plenum. Proposed and attempted chemical and hydraulic techniques for cleaning the internal surfaces of a slice plenum have produced disappointing results. Mechanical scouring is eventually required.
It is, therefore, an object of the present invention to provide a method by which a manually inaccessible slice plenum may be mechanically scoured.
Another object of the present invention is to provide a tool by which a manually inaccessible slice plenum may be mechanically scoured.
Another object of the present invention is to provide remote mechanical method for cleaning inaccessible papermachine headbox internal surfaces without damaging highly polished steel surfaces.